In modern circumstances, it is difficult and expensive to train soldiers and military defense personnel in the effective use of high-powered rapid-fire machine guns, by simply allowing such individuals to practice using the actual guns with live ammunition. The ammunition rounds are expensive, for example costing up to five dollars per round. The cost of ammunition alone quickly multiplies when it is recognized that a typical machine gun is capable of firing hundreds of rounds per minute. Adequate space for a practice gunnery range may not be readily available. Increased cost is involved in transporting the personnel and the equipment to suitable remote locations where adequate gunnery practice can be performed. Safety is always a major consideration when live ammunition rounds are fired, both to military personnel involved in gunnery practice and to non-military personnel who may be adjacent to the gunnery range. It is difficult to instruct during a live ammunition training session due to the noise and safety considerations involved when others are involved in similar, close-by, live-ammunition practice activities. Furthermore, it may be difficult to vary the targets quickly at a live-ammunition gunnery range.
These problems and practical constraints are exacerbated when training individuals to shoot from a moving vehicle such as a helicopter. If live ammunition practice is attempted from a moving helicopter, a large space is required in order to maneuver the helicopter and to provide targets and adequate safety barriers, especially when multiple individuals are involved in similar simultaneous training exercises. As a result, live gun practice requires considerabe space, and the cost of operating the helicopter greatly multiplies the overall training cost.
Because of these and other considerations, simulated weapon training programs have been developed for teaching purposes. Such training programs use imitation machine guns which closely simulate the sensational aspects and the mechanical and physical requirements of firing actual machine guns. Firing is simulated by reproducing effects which mirror the sensual perceptions associated with firing the actual machine gun. The environment and the targets are electronically displayed, allowing them to be more easily varied and to simulate movement of the targets and the machine gun. The trajectory of the simulated bullet fired is also calculated. In those cases where the simulated fired bullet emulates a tracer, the trajectory of that simulated bullet is also displayed in the surrounding environment.
For helicopter gun training, the imitation machine gun is mounted in an open door of an imitation portion of the helicopter fuselage. The environment and the targets are displayed outside of the open door. The portion of the imitation helicopter fuselage is moved or shaken in a manner similar to the movement of an actual helicopter in flight while the display of the surrounding environment and the targets are moved to simulate the flight path of the helicopter.
Simulated weapons training programs offer other benefits. Environments of remote areas of the world may be simulated, thereby providing training exposure to such environments prior to actually deploying the military personnel to those locales. The accuracy of the training program and the abilities of the individuals trained may be assessed. The accuracy in shooting, and the success of the training itself, is gauged by comparing the calculated, projected trajectory of the simulated bullets relative to the displayed targets. The number of simulated rounds fired may also be counted to evaluate the efficiency of the individual doing the shooting. Other factors can be evaluated from the vast amount of information available from such computer-based simulated weapons training programs.
Of course, to be effective for training purposes, it is necessary to create a realistic simulated environment and a realistic experience of firing the imitation machine gun. Such simulation is accomplished principally by multiple computer systems which are programmed to perform their specific simulation activities in coordination with each other. In the end, the capability of the simulated weapons training program to imitate the actual use of the actual machine gun in an actual environment is the ultimate measure of effective and successful training.
Individuals become accustomed to the imitation machine gun due to the amount of simulated training received. Because of the familiarity gained from training with the imitation machine gun, use of the imitation machine gun should be essentially the same as the use of the actual machine gun; otherwise, differences in functionality or performance create unexpected problems or difficulties when using the actual machine gun.
One action which must be trained to accurately simulate the use of an actual machine gun is loading an ammunition belt into the machine gun. Ammunition is supplied to the machine gun from an ammunition belt. To commence firing, the ammunition belt must be properly loaded into the machine gun. Each ammunition belt has a predetermined number of rounds, and when that number of rounds has been fired, it is necessary to load a new ammunition belt to continue firing. During intensive use, it is necessary to repetitively load ammunition belts, and do so quickly. Effective training with an imitation machine gun therefore requires the user to load ammunition belts, and do so on a repetitive and intensive basis.
To load an ammunition belt in an actual machine gun, a cover at the top of a housing of the machine gun is opened to expose a feed tray which pivots slightly upward when the cover is opened. An ammunition box which contains the ammunition belt is placed on a support tray which extends from the side of the machine gun. A door on the top of the ammunition box is opened, and the leading end of the ammunition belt is withdrawn from the open ammunition box. The leading rounds of the ammunition belt are placed on the feed tray, and the cover is then closed over the ammunition belt. The leading rounds of the ammunition belt are thereby positioned within an ammunition belt feedway of the machine gun to interact with a bolt of the machine gun.
To commence firing an actual machine gun, the bolt must be “charged” by manually pulling a charging handle rearwardly. Charging the bolt moves the bolt rearward against the force of an internal bolt actuating spring. Charging the bolt also removes the first round from the ammunition belt, moves the removed round into position on the bolt, and when the trigger is pulled enables the compressed bolt actuating spring to drive the bolt forward to load the round into a firing chamber and then fire that loaded round. The explosive force from firing the round drives the bolt rearward against the force of the bolt actuating spring. The rearward movement of the bolt automatically ejects the spent casing, withdraws the next live round from the ammunition belt, expels a connection link which joined the withdrawn round to the next round of the ammunition belt, positions the withdrawn round on the bolt for loading and firing, and advances the ammunition belt to locate the next round to undergo similar actions after active round has been fired. This sequence of events repeats with each subsequent pull of the trigger, or repeats automatically while the trigger remains depressed.
Unlike an actual machine gun, the imitation machine gun does not reciprocate the bolt, eject simulated casings, expel belt connecting links, or advance the next simulated round from the simulated ammunition belt. However, the imitation machine gun does require charging the bolt to enable the simulated firing of the first simulated round of a newly-loaded simulated ammunition belt. The bolt is held in the charged position against the force of the compressed bolt actuating spring while simulated rounds are fired. A recoil simulation device creates recoil impacts which simulate firing each ammunition round and the reciprocating motion of the bolt in an actual machine gun, by shaking or reciprocating the imitation machine gun in a forward and backward motion. One very effective recoil simulation device is described in the first above-referenced US patent application.
After all of the predetermined number of rounds of an actual ammunition belt have been fired simulatively from the imitation machine gun, as determined by counting the number of recoil impacts generated by the recoil simulation device, a bolt capture and release mechanism releases the bolt to allow the compressed bolt actuating spring to drive the bolt forward, thereby placing the bolt in position for charging after another ammunition belt has been loaded. One very effective bolt capture and release mechanism is described in the second above-referenced US patent application.
Simultaneously with the release of the bolt, an ammunition belt capture and release mechanism releases the simulated ammunition belt from the ammunition belt feedway of the imitation machine gun. A spring attached to the trailing end of the simulated ammunition belt withdraws the released simulated ammunition belt from the feedway and returns the entire simulated ammunition belt back into the open ammunition box. In the actual machine gun, firing all the rounds of the ammunition belt consumes the belt so that it no longer exists when the last round is fired. In the simulated machine gun, the simulated ammunition belt is withdrawn into the ammunition box when the last simulated round is fired. In both the imitation and actual machine guns, loading a new ammunition belt is required to continue firing.
One known device for capturing and releasing a simulated ammunition belt in an imitation machine gun uses a solenoid with a fork-like member connected to an armature of the solenoid. A compression spring surrounds the armature and forces the fork-like member to project into the space between two adjacent ammunition rounds in the simulated ammunition belt, thereby holding the simulated ammunition belt in the ammunition belt feedway. The force from the compression spring must hold the fork-like member between the two adjacent ammunition rounds under the influence of the repetitive impacts created by the recoil simulation device. However, in the previous device, the vibration from the recoil impacts gradually separates the fork-like member from within the space between the two rounds, causing a premature release of the simulated ammunition belt.
If the force from the compression spring is increased to maintain the fork-like member between the two rounds of the simulated ammunition belt under the influence of the recoil impacts, the solenoid must generate enough force to overcome the force from the compression spring to release the simulated ammunition belt when all the simulated rounds have been fired. A solenoid capable of generating sufficient force to overcome the force from the compression spring is physically large in size. Such a solenoid is too large to be integrated within the housing of the imitation machine gun without interfering with the other internal components of the imitation machine gun, such as the bolt. Consequently, the large solenoid of the prior art ammunition belt capture and release mechanism is attached to the exterior of the housing of the imitation machine gun at a position adjacent to the ammunition belt feedway.
Locating the prior art ammunition belt capture and release mechanism on the exterior of the housing of the imitation machine gun creates mechanical and use differences between the actual and simulated machine guns. The actions required to load the simulated ammunition belt in the simulated machine gun are different from the actions required to load the actual ammunition belt in the actual machine gun. In an actual machine gun, the ammunition belt is retained in the ammunition belt feedway by internal devices within the housing of the machine gun after the cover has been closed. In the imitation machine gun, the user must assure that the ammunition belt is properly located relative to the exterior mechanism. The user must also assure that the simulated ammunition belt continues to interact properly with the fork-like member connected to the solenoid armature, such as by occasionally repositioning, holding or manipulating the simulated ammunition belt. Such dissimilarities between the imitation and actual machine guns increase the risk of incorrectly and inefficiently loading actual ammunition belts when using the actual machine gun, and also detract from effective training due to the additional actions required to manipulate the simulated ammunition belt that are not required when using an actual machine gun.
A prior art ammunition belt capture and release mechanism with a less forceful compression spring and solenoid typically releases the simulated ammunition belt prematurely, which also causes dissimilarities between training and actual use, because the operator of the imitation machine gun is required to re-load the ammunition belt on a more frequent or erratic basis than would be the case if using an actual machine gun. Further still, the premature release of the ammunition belt has the potential to adversely influence the computer system which anticipates firing the full number of simulated rounds of the simulated ammunition belt. A premature release of the simulated ammunition belt also has the potential of adversely impacting the coordination between the other computer systems of the training simulator, thereby disrupting or detracting from the entire training experience.